Most sociohistorical interpretations of art view a body of work as the production of a class, generally a dominant or governing class, imposing its ideals.
Central Topic / Purpose
The relationship between art and the elites / to clarify a misconception
Main Point
While Taruskin and other sociohistorical interpreters of art think that the relationship between art and elites is one in which artists expressed the ideals of the elites for whom they were making art, there are reasons to think that in many cases this relationship doesn't hold.
Passage Map
P1 - Introduces the mainstream view (art = representation of elites' ideals) and offers thesis that there's more to the story.
P2 - Presents the "two ways" - 1. You hired an artist because they're trendy/famous and so it'll help your reputation. 2. You hired an artist to create something that embodies your ideals.
P3 - Clarification that the 2nd way is what the mainstream uses, and then possible problems with the second way.
P4 - Calling into question the presupposition that elites even had ideals or good taste in art, undermining a necessary assumption of "the 2nd way".
P5 - Bringing up cases where the artists specifically disobeyed the wishes of the elite, and showing how the 2nd way analysis would be particularly ill-conceived here.
Other Commentary
The first sentence has a huge foreshadowing clue as to the purpose / main point of the passage, since it starts with "most X's have done Y". That almost always leads into an author's pivot (but, yet, however, recently), just as it does in the end of the first paragraph.
The 4th paragraph of this passage is the hardest to understand for me, because it's attempting to undermine the idea that the elites even had something that we could call ideals, yet it seems to really just attack them in terms of how poor their taste in art was and how barbaric and low-brow some of their activities were.
The "Freudian analysis" line in the final paragraph is also very tricky. The author is saying,